﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class Person
{
    private string name;
    private int? age;

    public int? Age
    {
        get { return age; }
        set { age = value; }
    }

    public string Name
    {
        get { return name; }
        set { name = value; }
    }

    public Person()
    {
        this.name = null;
        this.age = null;
    }

    public Person(int age, string name)
    {
        this.age = age;
        this.name = name;
    }

    public Person(string name)
    {
        this.age = null;
        this.name = name;
    }

    public override string ToString()
    {
        StringBuilder result = new StringBuilder();
        result.Append(String.Format("The name of the person is {0}",this.name));
        if (this.age == null)
        {
            result.Append(" and age are not specified.");
        }
        else
        {
            result.Append(String.Format(" and is {0} years old.",this.age));
        }
        return result.ToString();
    }
}
